Manufacture of data storage device

ABSTRACT

A device and method for preparing media discs ( 2 ) in which servowriting and verification of the media may be carried out simultaneously. A common monolithic platform ( 1 ) is provided which supports air bearing systems which allow movement of a media disc rotary carrier ( 5 ), a servowriting headstack ( 3 ) and certifier headstack ( 4 ). Indirect drive may be provided to the rotary carrier ( 5 ) via coupling means ( 62 ).

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to the manufacture of data storage devices suchas magnetically and optically written discs. Examples are hard andfloppy magnetic discs as used in personal computers where the data iswritten in magnetically as well as CD ROMs which normally have datawritten in optically, i.e. usually by laser beam.

The invention relates specifically to the stage of manufacture of thestorage device where indexed tracks or sectors are created. These arenecessary so that the data recording and reproducing systems canidentify the location of data put into and read out from the storagedevice. Moreover for high quality performance these indexed tracks orsectors have to be very accurately provided on the storage device.

This manufacture involves separate stages wherein the media is examined(certified) and written to (servo written). Current practice requiresseparate discrete pieces of equipment to perform these tasks at separatestages of manufacture.

The tasks all require the rotation of the media disc with extremequality of motion while magnetic or other heads and sensors are movedacross the surface with controlled motion, positional relationships andgeometry. In this regard there are normally two separate units, one ofwhich, generally referred to as a servo-writer writes the sectors to thedisc, and the other, generally referred to as a verifier, verifies thesurface(s) of the disc, usually optically.

The aim of this invention is to provide a particularly accurate andsimple arrangement for performing these tasks, and accordingly theinvention provides a single platform with the ability to carry all thesystems required to perform these tasks, particularly to both verify thesurface and write the sectors, at one stage within the manufacturingprocess.

Accordingly one aspect of the invention comprises a single monolithicsupport platform, a rotary carrier arranged for rotation of a media discsupported on said platform, a write head arranged for substantiallyradial movement relative to said carrier and for servo writing of datato said media disc and a certifier head arranged for substantiallyradial movement relative to said carrier and for verification of themedia disc.

For the ultimate in quality of motion some or preferable all such motionsystems should be carried on air bearings. In a preferred constructionthe mountings for all of these air-bearing systems should be a singleand solid component incorporating the maximum rigidity providing acommon datum for each discrete process.

Accordingly a preferred form of the present invention utilises a singlebody to carry all the air bearing systems required to perform all theprocesses needed for the media to be installed in a disc drive or otherdata storage device. All motion systems thus contained can then becapable of simultaneous operation.

Respective drive means are typically provided for driving each of themoving components, namely, the rotary carrier, the write head andcertifier head. One or more of the drive means may comprise anintegrated motor which is arranged for directly driving a rotaryspindle, or other member, supporting the respective component. Providingintegrated drive means eases manufacture and alignment of theconstituent parts of the device.

One or more of the drive means may be an indirect drive means comprisinga motor which is mounted independently of the respective component, andcoupling means for transferring the drive to the respective componentwhilst minimising the transmission of any undesirable vibration. In someembodiments, the coupling means may be a resilient coupling meansdisposed in substantially axial alignment with a rotary spindle of therespective component. In other embodiments, the coupling means maycomprise a drive belt.

It is particularly preferred that indirect drive means are provided fordriving the rotary carrier carrying the media disc. The use of indirectdrive means can allow substantial mechanical isolation of the motor fromsensitive parts of the device. In particular, the indirect drive canhelp to prevent harmful vibrations being transmitted to the media discor the servowriter head, which might otherwise cause track errors.

According to another aspect of the invention there is provided a methodof preparing media storage discs comprising the steps of mounting amedia disc on a rotary carrier supported on a platform, verifying theintegrity of the mounted media disc using a certifier head andservowriting data to the mounted media disc with the write head withoutremoving the media disc from the rotary carrier between the verifyingand servowriting steps.

According to yet another aspect of the invention there is provided adevice for preparation of a media storage disc comprising a singlemonolithic support platform, a rotary carrier arranged for rotation of amedia disc supported on said platform, a write head arranged forsubstantially radial movement relative to said carrier and for servowriting of data to said media disc, a certifier head arranged forsubstantially radial movement relative to said carrier and forconfirming the integrity of the medium of the disc and indirect drivemeans for driving the rotary carrier, the drive means comprising a motormounted independently of the rotary carrier, and coupling means fortransmitting the drive to the rotary carrier whilst minimizing thetransmission of any undesirable vibration.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of invention will now be described, by way of example only,with reference to the accompanying drawings in which:

FIG. 1 shows a perspective view of a combination magnetic discservowriter and certifier platform;

FIG. 2 is a schematic side view of part of the platform shown in FIG. 1,the platform being partly shown in section; and

FIG. 3 is a schematic side view of part of an alternative platform, thealternative platform being partly shown in section.

DETAILED DESCRIPTION

Referring particularly to FIG. 1, in a first embodiment, a commonmonolithic platform 1 is provided in the form of a single piece ofmaterial integrally forming a base support for three separate airbearing motion systems thereby guaranteeing the positional relationshipof each to the media being processed. This media in the form of amagnetic disc 2 is mounted on a motorised spindle 5 with integralposition feedback and disc clamping.

A servowriting headstack 3 is mounted on a rotary spindle carried by anair bearing and is geometrically positioned in relation to the mediaspindle 5 so as to mimic the final data storage product take offread-rotation relationship. It is fitted with an integral accuratemotion actuator and fittings for a separate position sensor. Themonolithic platform 1 acts as a spindle block for both the disc carrierand the servowriting headstack spindles.

A certifier headstack 4 is mounted on a linear air-bearing supportedslide with integral linear motor and fittings for a separate positionsensor. However, this motion system could also be of rotary design. Insuch a case the monolithic platform would also act as a spindle blockfor the certified headstack spindle.

FIG. 2 is a schematic side view of part of the device shown in FIG. 1,part of the platform 1 being shown in section to more clearly show themotorised spindle 5 used for carrying the magnetic disc 2. The magneticdisc 2 and selected other parts of the device are omitted in FIG. 2 forthe sake of simplicity.

The motorised spindle 5 generally comprises a rotary spindle or shaft 51mounted in an air bearing 52 for rotation and axially supported by anaxial bearing 53. Rotational drive of the rotary spindle 51 is providedby an integral motor. The integral motor comprises a stator 54 and arotor 55 which carries a plurality of permanent magnets 56 and which isformed integrally with the rotary spindle 51. Thus a direct drive isprovided to the rotary carrier of the magnetic disc 2. It can be notedthat all of the rotary carrier, the servowriting headstack and certifiedheadstack are mounted on the support platform 1.

FIG. 3 is a schematic side view of part an alternative embodiment. Thealternative embodiment is similar to that described above except thatthe rotary carrier of the magnetic disc is indirectly driven. Again, inFIG. 3, part of the platform 1 is shown in section to more clearly showthe motorised spindle 5, whilst the magnetic disc 2 and selected otherparts of the alternative device are omitted for the sake of simplicity.

In the alternative embodiment, the motorised spindle 5 similarlycomprises a rotary spindle or shaft 51 mounted in an air bearing 52 forrotation and axially supported by an axial bearing 53. Howeverrotational drive of the rotary spindle 51 is provided by an independentmotor 6. The independent motor 6 is mounted on the support platform 1but independently of the rotary spindle 51. Drive is transferred to therotary spindle by way of a pair of pulleys 61 and a drive belt 62. Thusan indirect drive is provided to the rotary carrier of the magnetic disc2 which can help to avoid undesirable vibrations being transmitted tothe media disc or servo writing headstack.

In alternatives, a different form of drive coupling may be providedbetween an independent motor and the rotary carrier of the magneticdisc. This may take the form of a resilient solid or a fluid basedcoupling. Typically such a coupling will be disposed in alignment withboth the axis of the rotary carrier and the axis of the motor.

In other alternatives, the independent motor in an indirect drive devicecan be mounted externally, and/or entirely independently of themonolithic platform block.

In further alternatives, one or more of the motion systems may not be ofan air bearing design but some form of mechanical device.

In operation of any of the embodiments described above, a newly machinedand finished disc or stack of discs will be loaded onto the mediaspindle disc clamp, after which the spindle will spin up to theoperating speed. The servowriting and certifying tasks are completelyindependent and may be carried out in any order or simultaneously.However, the certifying process, which is typically an opticalexamination of the disc surfaces, can be conducted much more quickly (inthe order of 20 seconds) than the servowriting (say 20 minutes). Thus itis sensible to either certify first or simultaneously with the start ofthe servowriting process. Preferably the servowriting and certifierheadstacks will start their motion simultaneously allowing the integrityof the medium to be confirmed and the servo pattern to be written ontothe disc. If the certifier identifies a faulty disc the process will bestopped and the disc discarded. After the process is complete the mediawill be ready for assembly into a disc drive or other data storagedevice. Using a device of the type described herein, it is possible toachieve track densities in the order of 40,000 tracks per inch.

Although not described in detail, systems similar to those described andwithin the scope of the present invention can be used for processingother types of media discs.

1. A device for preparation of a media storage disc comprising a singlemonolithic support platform, a rotary carrier arranged for rotation of amedia disc supported on said platform, a write head arranged forsubstantially radial movement relative to said carrier and for servowriting of data to said media disc and a certifier head arranged forsubstantially radial movement relative to said carrier and forverification of the media disc.
 2. A device to claim 1 in which therotary carrier, the write head and the certifier head are all carried onair bearing systems.
 3. A device according to claim 2 in which mountingsfor each of said air bearing systems are formed within said singlemonolithic support platform, thereby ensuring a common datum for bothwriting to and verifying the disc.
 4. A device according to claim 2 inwhich at least one of the air bearings comprises a rotary spindle, andan associated indirect drive arrangement is provided for driving thespindle, the drive arrangement comprising a motor mounted independentlyof the respective spindle and coupling for transmitting the drive to therespective spindle whilst minimising the transmission of any undesirablevibration.
 5. A device according to claim 2 in which at least one of theair bearings comprises a rotary spindle, and associated indirect drivearrangement is provided for driving the spindle, the indirect drivearrangement comprising a motor mounted independently of the respectivespindle and a drive belt for transmitting the drive to the rotaryspindle.
 6. A device according to claim 1 comprising an indirect drivearrangement for driving the rotary carrier, the drive arrangementcomprising a motor mounted independently of the rotary carrier, and acoupling for transmitting the drive to the rotary carrier whilstminimising the transmission of any undesirable vibration.
 7. A deviceaccording to claim 6 in which the coupling comprises a resilientcoupling disposed in substantially axial alignment with the rotarycarrier.
 8. A device according to claim 6 in which the couplingcomprises a drive belt.
 9. A device according to claim 1 comprising anindirect drive arrangement for driving the rotary carrier, the drivearrangement comprising a motor mounted independently of the rotarycarrier, and a drive belt for transmitting the drive to the rotarycarrier.
 10. A device according to claim 1 which is arranged for writingto and verifying at least one of a hard magnetic disc, a floppy magneticdisc, and a CD Rom.
 11. A device according to claim 1, wherein saidcertifier head is arranged for confirming the integrity of the medium ofthe disc.
 12. A method of preparing media storage discs comprising thesteps of mounting a media disc on a rotary carrier supported on aplatform, verifying the integrity of the mounted media disc using acertifier head and servowriting data to the mounted media disc with awrite head without removing the media disc from the rotary carrierbetween the verifying and servowriting steps.
 13. A device forpreparation of a media storage disc comprising a single monolithicsupport platform, a rotary carrier arranged for rotation of a media discsupported on said platform, a write head arranged for substantiallyradial movement relative to said carrier and for servo writing of datato said media disc, a certifier head arranged for substantially radialmovement relative to said carrier and for confirming the integrity ofthe medium of the disc, and indirect drive means for driving the rotarycarrier, the drive means comprising a motor mounted independently of therotary carrier, and coupling means for transmitting the drive to therotary carrier whilst minimizing the transmission of any undesirablevibration.
 14. A device according to claim 13 in which the couplingmeans comprises a resilient coupling means disposed in substantiallyaxial alignment with the rotary carrier.
 15. A device according to claim13 in which the coupling means comprises a drive belt.
 16. A deviceaccording to claim 13 in which at least one of the rotary carrier, thecertified head and the write head is carried on an air bearing.
 17. Adevice for preparation of a media storage disc comprising: a singlemonolithic support platform, a rotary carrier supported on said platformand arranged for rotation of a media disc on an air bearing system, thecarrier being driven by a motor mounted independently of the rotarycarrier and arranged to drive the carrier via a resilient coupling; awrite head arranged for substantially radial movement relative to saidcarrier and for servowriting of data to said media disc, the write headbeing carried on an air bearing system; and a certifier head arrangedfor substantially radial movement relative to said carrier and forconfirming the integrity of the medium of the disc.
 18. A device forpreparation of a media storage disc comprising: a single monolithicsupport platform, a rotary carrier supported on said platform andarranged for rotation of a media disc on an air bearing system, thecarrier being driven by a motor mounted independently of the rotarycarrier and arranged to drive the carrier via a drive belt; a write headarranged for substantially radial movement relative to said carrier andfor servowriting of data to said media disc, the write head beingcarried on an air bearing system; and a certifier head arranged forsubstantially radial movement relative to said carrier and forconfirming the integrity of the medium of the disc.